A fluorinated hydroxyl compound is useful as a water and oil repellent, a surfactant or an intermediate for a color developing material for photograph (JP-A-54-154707). Further, a fluorinated hydroxyl compound does not dissolve a plastic substrate and thus is useful as a solvent for e.g. a dye for an optical recording material (JP-A-4-8585, JP-A-5-258346).
Heretofore, purification of a fluorinated hydroxyl compound has been carried out by distillation. However, when a compound having an unshared electron pair (hereinafter referred to also as an unshared electron pair compound) is included in the process for producing a fluorinated hydroxyl compound, such an unshared electron pair compound interacts with the fluorinated hydroxyl compound, whereby there has been a problem that it can not be separated by usual distillation separation. For example, when the unshared electron pair compound is an aliphatic alcohol such as t-butanol, there has been a problem that it can not be separated by usual distillation, even if there is a difference in boiling point between the fluorinated hydroxyl compound and the aliphatic alcohol.
Further, a method has been proposed wherein methanol is reacted with tetrafluoroethylene or hexafluoropropylene in the presence of a polymerization initiator to obtain a reaction product containing a fluorinated alcohol, which is then heated to decompose an unreacted polymerization initiator, followed by distillation (EP968989A). However, this method requires heating of the reaction product, and there has been a problem such that the unreacted polymerization initiator can not be recovered.
Further, a purification method is also proposed wherein a fluorinated alcohol containing water in an amount of not more than 2000 ppm, is distilled to remove water azeotropically or pseudoazeotropically to obtain a fluorinated alcohol as the residue (EP992476A). However, the fluorinated alcohol in such a method contains no unshared electron pair compound, and in such a method, the fluorinated alcohol is obtained as a residue, whereby there has been a problem that impurities which are likely to remain as evaporation residues, will remain in the fluorinated alcohol.